Influence of Fusarium virguliforme Temporal Colonization of Corn, Tillage, and Residue Management on Soybean Sudden Death Syndrome and Soybean Yield

The asymptomatic host range of Fusarium virguliforme includes corn, a common crop rotated with soybean that we hypothesize may alter F. virguliforme population dynamics and disease management. A field-based approach explored the temporal dynamics of F. virguliforme colonization of corn and soybean roots under different tillage and residue managements. Experiments were conducted in IA, IN, MI, WI, and Ontario, Canada from 2016 to 2018. Corn and soybean roots were sampled at consecutive time points between 1 and 16 weeks after planting (WAP). DNA was extracted from all roots and analyzed by real-time qPCR for F. virguliforme quantification. Trials were rotated between corn and soybean, containing a two x two factorial of tillage (no-tilled or tilled) and corn residue (with or without) in several experimental designs. In 2016, low (ca. 100 fg/10 mg root tissue) F. virguliforme was detected in the inoculated IA, IN and MI locations, and non-inoculated WI corn fields. However, in 2017 greater levels of F. virguliforme DNA were detected in IA, IN and MI across sampling time points. Tillage practices showed inconsistent effects on F. virguliforme root colonization and SDS foliar symptoms among trials and locations. Yet, residue management did not alter root colonization of corn or soybean by F. virguliforme. Plots with corn residue had greater SDS foliar disease index in Iowa in 2016. However, this trend was not observed across the site-years, indicating corn residue may occasionally increase SDS foliar symptoms depending on the disease level, soil and weather factors.

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Temporal Dynamics of Fusarium virguliforme Colonization of Soybean Roots

Plant Disease ◽

10.1094/pdis-03-18-0384-re ◽

2019 ◽

Vol 103 (1) ◽

pp. 19-27 ◽

Cited By ~ 10

Author(s):

Jie Wang ◽

Janette L. Jacobs ◽

Mitchell G. Roth ◽

Martin I. Chilvers

Keyword(s):

Field Experiments ◽

Root Colonization ◽

Temporal Dynamics ◽

Sample Collection ◽

Fusarium Virguliforme ◽

Soybean Cultivars ◽

Foliar Symptoms ◽

Foliar Resistance ◽

Soybean Roots ◽

Collection Point

Soybean sudden death syndrome (SDS) caused by Fusarium virguliforme is one of the most yield limiting soybean diseases in the United States. SDS disease symptoms include root rot and foliar symptoms induced by fungal toxins. Soybean cultivar resistance is one of the most effective SDS disease management options, but no cultivar displays complete resistance. Soybean SDS foliar symptoms are the primary phenotype used to screen and breed for SDS resistance. Root rot or root colonization measures are seldom utilized, partly due to the lack of convenient and accurate methods for quantification of F. virguliforme. In this study, greenhouse and field experiments were conducted to determine the temporal dynamics of F. virguliforme colonization of soybean roots using quantitative real-time PCR (qPCR). The infection coefficient (IC), or ratio of F. virguliforme DNA to soybean DNA, was determined in soybean cultivars with different SDS foliar resistance ratings. In greenhouse experiments, F. virguliforme was detected in all cultivars 7 days after planting (DAP), with a peak in IC at 14 DAP. All soybean cultivars developed SDS foliar symptoms, but F. virguliforme soybean root colonization levels did not significantly correlate with SDS foliar symptom severity. In field experiments, SDS foliar symptoms developed among soybean cultivars in alignment with provided foliar resistance ratings; however, the F. virguliforme IC were not significantly different between SDS foliar symptomatic and asymptomatic cultivars. F. virguliforme was detected in all cultivars at the first sample collection point 25 DAP (V3 vegetative growth stage), and the IC increased throughout the season, peaking at the last sample collection point 153 DAP (postharvest). Collectively, appearance and disease severity ratings of SDS foliar symptoms were not associated with F. virguliforme quantity in roots, suggesting a need to include F. virguliforme root colonization in breeding efforts to screen soybean germplasm for F. virguliforme root infection resistance. The findings also demonstrates root colonization of the pathogen on nonsymptomatic soybean cultivars leading to persistence of the pathogen in the field, and possible hidden yield loss.

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Interactions Between the Soybean Cyst Nematode and Fusarium solani f. sp. glycines Based on Greenhouse Factorial Experiments

Phytopathology ◽

10.1094/phyto-96-1409 ◽

2006 ◽

Vol 96 (12) ◽

pp. 1409-1415 ◽

Cited By ~ 26

Author(s):

X. Gao ◽

T. A. Jackson ◽

G. L. Hartman ◽

T. L. Niblack

Keyword(s):

Fusarium Solani ◽

Soybean Cyst Nematode ◽

Root Colonization ◽

Cyst Nematode ◽

Fungal Colonization ◽

Foliar Symptoms ◽

Progress Curve ◽

Soybean Roots ◽

Polymerase Chain ◽

Low Levels

The soybean cyst nematode, Heterodera glycines, and the fungus that causes sudden death syndrome (SDS) of soybean, Fusarium solani f. sp. glycines, frequently co-infest soybean (Glycine max) fields. The interactions between H. glycines and F. solani f. sp. glycines were investigated in factorial greenhouse experiments with different inoculum levels of both organisms on a soybean cultivar susceptible to both pathogens. Measured responses included root and shoot dry weights, H. glycines reproduction, area under the SDS disease progress curve, and fungal colonization of roots. Both H. glycines and F. solani f. sp. glycines reduced the growth of soybeans. Reproduction of H. glycines was suppressed by high inoculum levels but not by low levels of F. solani f. sp. glycines. The infection of soybean roots by H. glycines did not affect root colonization by the fungus, as determined by real-time polymerase chain reaction. Although both pathogens reduced the growth of soybeans, H. glycines did not increase SDS foliar symptoms, and statistical interactions between the two pathogens were seldom significant.

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Winter soil microclimate altered by corn residue management in the northern Corn Belt of the USA

Soil and Tillage Research ◽

10.1016/s0167-1987(98)00181-0 ◽

1998 ◽

Vol 49 (3) ◽

pp. 243-248 ◽

Cited By ~ 19

Author(s):

B.S Sharratt ◽

G.R Benoit ◽

W.B Voorhees

Keyword(s):

Residue Management ◽

Corn Belt ◽

The Usa ◽

Corn Residue ◽

Soil Microclimate

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Effect of N Fertilizer and Corn Residue Management on Organic Matter in Minnesota Mollisols 1

Agronomy Journal ◽

10.2134/agronj1982.00021962007400010046x ◽

1982 ◽

Vol 74 (1) ◽

pp. 161-163 ◽

Cited By ~ 9

Author(s):

P. R. Bloom ◽

W. M. Schuh ◽

G. L. Malzer ◽

W. W. Nelson ◽

S. D. Evans

Keyword(s):

Organic Matter ◽

N Fertilizer ◽

Residue Management ◽

Corn Residue

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Effect of Tillage, Residue Management and Cropping System on the Properties of Soil

International Journal of Applied Sciences and Biotechnology ◽

10.3126/ijasbt.v6i2.20433 ◽

2018 ◽

Vol 6 (2) ◽

pp. 164-168 ◽

Cited By ~ 3

Author(s):

Bibek Thapa ◽

Keshab Raj Pande ◽

Baburam Khanal ◽

Santosh Marahatta

Keyword(s):

Cropping System ◽

Conservation Agriculture ◽

Conventional Tillage ◽

Residue Management ◽

Zero Tillage ◽

Tillage Practices ◽

Residue Removal ◽

Main Plot ◽

Residue Retention

A field experiment was conducted to evaluate the effect of tillage practices, residue management and cropping system on soil properties at NMRP, Rampur, Chitwan from November 2015 to April 2016. The experiment was laid on Strip split design with combination of 12 different treatments i.e, zero tillage & conventional tillage as main plot in the strip, residue retention & residue removal as sub-plot factor and maize – wheat, maize + soybean – wheat & soybean – wheat cropping system as sub-sub plot factor. Three replications of the treatments were made. Soil sample before experiment and after harvest of wheat was taken (0-15cm). The experiment showed significant effect of zero tillage on organic carbon (2.169%) and on total soil nitrogen (0.112 %). Zero tillage with retention of residues is valuable tool for the conservation agriculture and helps in sustainability of soil however long-term research for the tillage management and residue retention should be conducted to highlight the major effects on change in properties of soil.Int. J. Appl. Sci. Biotechnol. Vol 6(2): 164-168

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Corn Residue Management and Soil Organic Matter 1

Agronomy Journal ◽

10.2134/agronj1979.00021962007100040025x ◽

1979 ◽

Vol 71 (4) ◽

pp. 625-627 ◽

Cited By ~ 97

Author(s):

Stanley A. Barber

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Residue Management ◽

Corn Residue

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A3T-GCN: Attention Temporal Graph Convolutional Network for Traffic Forecasting

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi10070485 ◽

2021 ◽

Vol 10 (7) ◽

pp. 485

Author(s):

Jiandong Bai ◽

Jiawei Zhu ◽

Yujiao Song ◽

Ling Zhao ◽

Zhixiang Hou ◽

...

Keyword(s):

Road Network ◽

Temporal Dynamics ◽

Technological Problem ◽

Traffic Flows ◽

Convolutional Network ◽

Temporal Dimension ◽

Time Points ◽

The Road ◽

Traffic Forecasting ◽

Temporal Graph

Accurate real-time traffic forecasting is a core technological problem against the implementation of the intelligent transportation system. However, it remains challenging considering the complex spatial and temporal dependencies among traffic flows. In the spatial dimension, due to the connectivity of the road network, the traffic flows between linked roads are closely related. In the temporal dimension, although there exists a tendency among adjacent time points, the importance of distant time points is not necessarily less than that of recent ones, since traffic flows are also affected by external factors. In this study, an attention temporal graph convolutional network (A3T-GCN) was proposed to simultaneously capture global temporal dynamics and spatial correlations in traffic flows. The A3T-GCN model learns the short-term trend by using the gated recurrent units and learns the spatial dependence based on the topology of the road network through the graph convolutional network. Moreover, the attention mechanism was introduced to adjust the importance of different time points and assemble global temporal information to improve prediction accuracy. Experimental results in real-world datasets demonstrate the effectiveness and robustness of the proposed A3T-GCN. We observe the improvements in RMSE of 2.51–46.15% and 2.45–49.32% over baselines for the SZ-taxi and Los-loop, respectively. Meanwhile, the Accuracies are 0.95–89.91% and 0.26–10.37% higher than the baselines for the SZ-taxi and Los-loop, respectively.

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Microbiological and FTIR applications in Atlantic forest regeneration areas

10.5194/egusphere-egu2020-22032 ◽

2020 ◽

Author(s):

Laura Borma ◽

Breno Pupin ◽

Kumiko Sakani

Keyword(s):

Infrared Spectroscopy ◽

Atlantic Forest ◽

Mycorrhizal Fungi ◽

Forest Regeneration ◽

Root Colonization ◽

Temporal Dynamics ◽

Spore Density ◽

Water Retention Capacity ◽

Microbial Quality ◽

Regeneration Processes

Soil regulates plant productivity in terrestrial ecosystems and maintains the balance of biogeochemical cycles through biotransformations mediated by living organisms, which are responsible for 80 to 90% of these functions. Therefore, it is necessary to evaluate whether restoration/natural regeneration processes in land degraded areas may allow the soil to partially or fully recover its microbial functions reflecting thus, in the fertility of these soils and consequently in the regeneration of forests. The use of microbiological attributes combined with infrared spectroscopy (FTIR) offers many opportunities to understand temporal dynamics and spatial variability in the recovery of important ecosystems during forest regeneration stages.The present work aims to evaluate the evolution of microbial quality in soils under three Atlantic Forest areas at different stages of regeneration (R40 - advanced, R12 - intermediate and RP - early regeneration pasture area) located in S&#227;o Paulo state, Brazil. We used as indicators of the soil microbial quality the number of colony-forming units (CFU) of total bacteria and fungi, spore density and root colonization by arbuscular mycorrhizal fungi (AMF). We also analyzed these soils by Fourier Transform Infrared Spectroscopy (FTIR-UATR). For each area, seven soil samples and plant roots were randomly collected at a depth of 0-20 cm at the end of the dry season (October 2019). In terms of dry soil, the CFU bacteria for each area was, respectively, 7.7, 4.6 and 3.2 x 105 CFU g-1; fungi, 1.2, 1.0 and 0.6 x 103 g-1,&#160;and AMF spore density, 39, 33 and 27 spores 50 ml-1. On average, AMF root colonization was 26 (R40), 25 (R12) and 21% (PR). For the FTIR spectrum, the major bands and their assignments were identified as a 3.370 cm-1 wide band assigned to the O-H groupings; a peak at 1.635 cm-1 attributed to aromatic C=C vibration, with contribution of C=O of the COO- and a peak at 1.072 cm-1 attributed to the carbohydrate C-O bond. No difference was attributed to the composition of the main functional groups (O-H, C=O, COO- and C-O) between the soils from R40 and R12, but this difference was more evident when compared to the RP area.&#160; The microbiological results show good similarity between the tree areas in terms of spores, fungi and root colonization. However, in terms of bacteria, there is a more pronounced difference between the recent (RP) and the older regeneration areas (R12 and RP). Similar pattern was pointed by the FTIR&#160;results. Considering pasture as a strongly degrading area, these results are interesting since they show the differences in the soil quality between the three areas is not highly pronounced. They also show that in twelve years of regeneration, in many aspects&#8217; soils become similar to the area with forty years regeneration. Given these results, a further investigation on soil physics of these areas is being developed to relate soil regeneration processes and soil physical properties such as porosity, density and water retention capacity, all of them important to the maintenance of vegetation and ecosystem services of water and climate regulation.

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